DE102024102817B3 - Projectile against aluminum alloy structures - Google Patents

Abstract

Projectile (1) against structures made of aluminium alloys, with the following features:
a) the projectile (1) is a ballistic projectile,
b) the projectile (1) has a chamber (2),
c) the chamber (2) contains gallium (25) to damage aluminum alloy structures.
Suitable calibers range from 5 to 30 mm.

Description

The invention relates to a projectile against structures made of aluminum alloys.

Aluminum alloys are widely used in vehicle and aircraft construction. Attacking aluminum alloy structures is part of the normal target spectrum of introduced munitions. Improving the effectiveness of the munitions on target is always the goal of product improvements.

The interaction between gallium and aluminum results in an unusual property known as the "gallium-aluminum intermetallic compound." Gallium has the ability to infiltrate aluminum, forming a brittle intermetallic compound. When gallium comes into contact with aluminum, it diffuses into the aluminum structure, forming an intermetallic phase. This intermetallic compound has lower strength and hardness compared to pure aluminum. The result is that the aluminum loses strength and becomes more brittle. This effect can lead to structural problems, especially when aluminum components come into contact with gallium. It is important to note that the interaction between gallium and aluminum does not occur immediately but develops over time. The rate and effects of this process depend on several factors, including temperature, gallium concentration, and duration of contact. This property of gallium makes it a potential pollutant or contaminant for aluminum alloys.

A publication ( Bonnet, Martin (2021): Nonviolent Destruction of an Aluminum Lock with Gallium. In: YouTube Channel World of Materials. Available online at: https://www.youtube.com/watch?app=desktop&v=XdqXJvuWG4o .) illustrates the effect of gallium on an aluminum alloy.

The DE 10 2004 017 466 A1 shows a ballistic projectile with a chamber containing a colored powder to mark the point of impact.

The DE 10 2010 044 001 B3 concerns the field of hailstorm investigations. Projectiles made of frozen water are used for this purpose.

The US 2010 / 0 083 860 A1 refers to a ballistic, non-lethal projectile. The projectile is filled with a flowable payload, such as a liquid gallium alloy. At the moment of impact, an internal hydrodynamic structure forces the flowable charge to move radially from the center to the periphery and against a weakened area. This facilitates rupture and reduces the projectile's pressure on a target surface to temporarily incapacitate an attacker.

The DE 10 2012 002 687 A1 refers to a garnet with a tracer. The tracer may include indium gallium arsenide (InGaAs). InGaAs is a photoluminescent material.

The DE 699 32 720 T2 refers to a metal projectile for shooting training. The metal projectile contains metal particles. A binder binds the metal particles together. One of several components of the binder can be gallium.

The DE 10 2020 133 371 A1 refers to a full metal jacket bullet which may be provided with a substance which causes a chemical reaction when the full metal jacket bullet hits a target.

The DE 295 03 118 U1 refers to a bomb that uses an adhesive instead of explosives to limit the mobility of people and military equipment.

The invention is based on the object of creating a projectile to damage structures of certain metal alloys.

This object is achieved according to the invention by the features of claim 1.

• das Geschoss gegen Strukturen aus Aluminiumlegierungen ist ein ballistisches Geschoß,
  • • das Geschoss weist eine Kammer auf,
  • • die Kammer enthält Gallium.

The advantages of the invention are based on the following features:

• the projectile against structures made of aluminum alloys is a ballistic projectile,
  • • the bullet has a chamber,
  • • the chamber contains gallium.

To combat protective structures made of aluminum alloys, it is proposed to use projectiles with an effective filling of elemental gallium. The impact of such a projectile on an aluminum alloy structure brings the gallium into direct contact with the aluminum alloy. Metallic gallium, due to its high wettability, has the property of penetrating deep into aluminum alloys and severely weakening their intercrystalline cohesion. Although this effect is not immediate, the damage is not visible to an enemy and, after a few hours, leads to significant damage to the structure, whose strength decreases significantly. The damage process is not easily detectable and is also irreversible. The protective effect of the structure being shot at is permanently reduced and progresses, imperceptibly from the outside. In aircraft, the loss of strength leads to device failure; in armored vehicles, ballistic protection drops significantly, even leading to structural disintegration under slight stress. This process is not easily reversible; it can only be stopped by removing the affected areas. The gallium contained in the chamber is surrounded by a protective container. A protective container prevents a chemical reaction of the gallium. This simplifies the manufacture and storage of the ammunition. The protective container has a simple inert plastic layer. The bullet has a bullet core, and the chamber is embedded in the bullet core. To produce ammunition containing gallium, it is merely necessary to modify an existing bullet core.

Building on the aforementioned design, the bullet core is an easily machined steel core. This allows for easy fabrication of the chamber for gallium.

• • Der Geschosskern weist ein Aufnahmeelement auf,
• • das Aufnahmeelement weist eine Sacklochbohrung auf, die den Schutzbehälter mit dem Gallium aufnimmt,
• • der Stopfen ist dazu ausgebildet, die Sacklochbohrung zu verschließen.

According to a further advantageous embodiment of the invention, the projectile has the following features:

• • The projectile core has a receiving element,
• • the receiving element has a blind hole that accommodates the protective container with the gallium,
• • the plug is designed to close the blind hole.

Production is simplified because it can be based on existing cartridges or ammunition. Instead of the traditional bullet core, there is now an assembly comprising the receiver, the plug, and the protective container containing the gallium. This arrangement ensures that the gallium only reaches the bare surface of an aluminum alloy structure in the desired manner upon impact with the target.

According to a further advantageous embodiment of the invention, the caliber of the bullet is 5 to 30 mm. Smaller calibers contain too little gallium. Larger calibers offer such a high impact energy that the gallium damaging effect is reduced.

• • ein Bugteil einer Patrone mit einem Geschoss mit einer Kammer mit Gallium, als Prinzipskizze und im Längsschnitt mit Ausbrüchen zur Illustration von Einzelheiten.

Embodiments of the invention are explained in more detail below with reference to the drawing. 1 , the only figure,

• • a nose section of a cartridge with a bullet chambered with gallium, as a schematic diagram and in longitudinal section with cut-outs to illustrate details.

The 1 shows a nose section of a cartridge with a projectile 1 against structures made of aluminum alloys. The projectile 1 is a ballistic projectile. The projectile 1 has a chamber 2. The chamber 2 contains gallium 25. The gallium 25 contained in the chamber 2 is surrounded by a protective container 20. The protective container 20 consists of an inert plastic layer made of polyethylene.

The bullet 1 has a bullet core 3. The chamber 2 is embedded in the bullet core 3. The bullet core 3 is a steel core. The bullet 1 is a bullet 1 of a modified 7.62 mm x 67 cartridge. Instead of the previous bullet core made of tungsten carbide, a two-part bullet core made of easily machined steel is now provided. The bullet core 3 has a receiving element 30 as its first part and a plug 35 as its second part. The receiving element 30 has a blind bore 31 that accommodates the protective container 20 containing the gallium. The plug 35 closes the blind bore 31. The lead filler 4, the bullet jacket 5, the propellant powder 8, and the propellant case 9 are adopted.

The functional sequence is described below.

A cartridge is in the breech of the weapon. Upon impact of the firing pin, the propellant powder 8 is ignited and burns. The projectile 1 is expelled from the propellant case 9 and accelerated in the weapon barrel. The projectile 1 hits the target. The target is a point on an aircraft skin. The aircraft skin is a sheet of aluminum alloy with an outer skin coating. Behind it are reinforcement elements made of an aluminum alloy. The sheet and reinforcement elements tear due to the impact. Bare surfaces of the aluminum alloy are formed. The projectile 1 is compressed. The protective container 20 breaks open. The gallium 25 escapes and wets bare areas of the sheet and the reinforcement elements. The gallium 25 damages the aluminum alloy structure as described above.

At least 5% by weight of the total weight of the projectile 1 is pure gallium to achieve effectiveness. An upper value is 80% by weight to ensure mechanical stability so that the protective container 20 only ruptures upon impact, releasing the gallium 25.

• - Der Geschosskern 3 weist ein Aufnahmeelement 30 und einen Stopfen 35 auf. Das Aufnahmeelement 30 weist eine Sacklochbohrung 31 auf, die den Schutzbehälter 20 mit dem Gallium 25 aufnimmt. Der Stopfen 35 verschließt die Sacklochbohrung 31. Entgegen der Darstellung kann der Stopfen 35 in Schussrichtung vorne sein und das Aufnahmeelement 30 in Schussrichtung dahinter.
• - Im Ausführungsbeispiel beträgt das Kaliber 7,62 mm. Das Geschoss 1 kann auch andere Kaliber im Bereich von 5 bis 30 mm aufweisen.
• - Der Schutzbehälter 20 nach 1 besteht aus einer einzigen, inerten Kunststoffschicht. Der Schutzbehälter kann zusätzlich zur inerten Kunststoffschicht noch weitere Schichten aufweisen.

The following deviations from the illustrated example are possible:

• - The projectile core 3 has a receiving element 30 and a plug 35. The receiving element 30 has a blind hole 31 which receives the protective container 20 with the gallium 25. The plug 35 closes the blind hole 31. Contrary to the illustration, the plug 35 can be at the front in the firing direction and the receiving element 30 behind it in the firing direction.
• - In the illustrated example, the caliber is 7.62 mm. Projectile 1 can also have other calibers in the range of 5 to 30 mm.
• - The protective container 20 according to 1 consists of a single, inert plastic layer. The protective container may have additional layers in addition to the inert plastic layer.

List of reference symbols

1

bullet

2

chamber

3

bullet core

4

packing

5

Bullet jacket

8

Propellant powder

9

Propellant case

20

Protective container

25

gallium

30

Receiving element

31

Blind hole drilling

35

Plug

Claims (4)

A projectile (1) for use against aluminum alloy structures, comprising: a) the projectile (1) is a ballistic projectile, b) the projectile (1) has a chamber (2), c) the chamber (2) contains gallium (25) to damage aluminum alloy structures, d) the gallium (25) contained in the chamber (2) is surrounded by a protective container (20), e) the protective container (20) has an inert plastic layer, f) the projectile (1) has a projectile core (3), and the chamber (2) is embedded in the projectile core (3). Floor (1) after Claim 1 , in which the bullet core (3) is a steel core. Floor (1) after Claim 1 or 2 , with the features: • the projectile core (3) has a receiving element (30) and a plug (35), • the receiving element (30) has a blind hole (31) which receives the protective container (20) with the gallium, • the plug (35) closes the blind hole (31). Floor (1) after one of the Claims 1 until 3 , wherein the projectile (1) has a calibre of 5 to 30 mm.

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